Insulating device for electrical connections



y 1934- c. B. CASE, JR 1,957,389

INSULATING DEVICE FOR ELECTRICAL CONNECTIONS Filed July 6. 1932 tom Patented May 1, 1&34

ENSULATING DEVICE FOR ELECTRICAL CONNECTIONS Charles B. Case, Jin, Trenton, N. J.

Application July 6, 1932, Serial No. 621,104

3 Claims.

My present invention, in its broad aspect, has to do with improvements in means for insulating the terminals of an electrical connection; and in its more specific application, it has to do with improvements in an insulating device which is separable from, and may be sold and merchandised separately with respect to, a conventional electric connection or fitting, such for instance as a terminal plug or socket.

I am well aware that it has heretofore been proposed to provide in what is known as a twopart electric plug, a partitioning and insulating member on one part of the plug for preventing short circuiting of the terminal Wires leading into the other part of the plug. However, the main objection to forming a plug element with a partitioning element forming an insulator, is that care must be taken when attaching the terminals in the other plug element to make allowances for the partition when the two plug elements are fitted together to complete the circuit. Furthermore this type. of plug is costly to manufacture; more or less intricate; and the retail price of necessity is increased or the profit to the retailer reduced. I am also aware that ordinary fibre, or bakelite insulating pieces are old in the form of flat washers; detachable posts; sleeves, specially formed terminals, and the like.

What I propose to do in my present invention, and have done as both experiments and actual practice have demonstrated; is to provide a simple, detachable, cheap and durable insulating member in the form of a circular, square or otherwise shaped fiat washer-like element having formed as part thereof, or integrally therewith, a partitioning insulating piece which is at rightangles to oneside thereof. The washer-like element having its insulating and partitioning'plate or piece extending from one side thereof may be formed of bakelite, fibre, rubber, or any other suitable insulating material, and it is designed to be manufactured, merchandised, and sold separately from the terminal plug and socket with which it is designed to be used, and assembled in the plug or socket when the circuit is completed by attaching the terminals to the posts of the plug or socket. While I have here spoken of my invention with reference to its use with a twopart electrical plug or socket it may be used with other electrical fittings and I speak for the purpose of making myself specifically clear rather than for purposes of limitation of the adaptation and use of the invention.

My insulating washer may be manufactured and sold at a fraction of a cent in price, and is especially adapted for retailing through five-andten cent stores, retail electrical stores and the like. Amateur electricians do not have the facilities or skill ordinarily to solder a plug terminal, and unless care is taken to properly attach an electric wire terminal to the post of a plug, short circuiting is almost sure to occur in time for many reasons. Continuous short circuiting (sometimes accompanied by injury and damage) often takes place with electric irons, toasters, table lamps, poachers, and the like. This is the type or device usually tinkered with by one unskilled with electrical practice. By the use of my invention short circuiting is absolutely prevented and a more fool-proof, practical, and efiicient terminal connection is provided.

While the foregoing I have set forth some of the main purposes advantages of my invention with reference to its practical application to certain specified types of electric connections; it is manifest that both the form, shape, size, and composition of my insulating washer may be changed without departing from the spirit of the invention, and it may be used with other types of electrical equipment not specifically enumerated.

In the drawing wherein a preferred form of my invention is illustrated:--

Figurel is a top plan view thereof;

Figure 2 is a side elevation;

Figure 3 is a perspective view; 85

Figure 4 is a view of an electrical plug assembly with my device partlyin section;

Figure 5 is a side view of a plug element showing my insulating device in place, and I Figure 6 is a top plan view of a plug element with my insulating device shown in place with respect to the terminals thereof.

In the drawing wherein like characters of reference are used to designate like or similar parts throughout the several views thereof; 95

The numeral (1) designates a flat, circular washer-like element which forms the body of my device. While the same is circular in shape, other forms may be used, and it may be made of bakelite, fibre or any other desired insulating material. Formed as part of the element (1) or integral therewith, is a plate like member (2) which rises at right angles from one side of the member (1) and extends to the edges thereof. While the plate-like member (2) is shown rectan- 105 gular, its shape may be changed or it may be cut down with a knife or shaped up along its edge to suit particular conditions when applied. The washer-like member (1) and the plate-like member (2) carried by the washer-like member form the complete unit, and they may be formed of an integral casting or stamping, or permanently attached to each other in any suitable manner.

The washer-like member has formed therein slots (3) which are preferably H-shaped to provide fingers (4) for frictionally engaging the terminals of a plug in the manner which will be hereinafter described.

In order to illustrate the application of my invention to one type of electrical fitting, I have shown in the drawing the male element of a conventional type of twopart electric plug, same being designated (5) and having the usual contact member (6); terminal posts ('7); lead in wires (8) to the terminal posts, and screw fastenings (9).

As shown in Figures 4, 5 and 6; the lead in wires (8) are attached to the terminal posts ('7) on opposite sides of the plug, adjacent each of the contact members (6) it is these lead in wires that are likely to short circuit unless the connections to the terminal posts ('7) are soldered or carefully made by an experienced electrician.

In order to prevent short circuiting, my present invention is used and applied after the following manner After the lead in wires have been connected to the terminal posts my insulating device is applied by fitting down the washer-like member over the contact members (6) so that they are received through the slots (3) as shown in views 5 and 6, in which case the plate-like partitioning and insulating member (2) fits down between the respective lead in wires (8) which are thus separated and insulated from each other and the interior of the plug is partitioned and insulated so that there is no possibility of chance contact between the lead in wires, terminals or the like on one side of the plug with those on the other; the position of my plate-like partitioning and insulating member (2) being shown with respect to the parts of a conventional plug in Figure 4.

It is believed that the operation, construction, and advantages of my invention will be clearly apparent from the foregoing, but it is emphasized that interpretation of the scope of my invention should only be conclusive when made in the light of the subjoined claims.

I claim;-

1. The combination with substantially any conventional terminal plug for electrical connections of the type having a body portion for the lead-in wires and spaced upstanding terminals; a detachable accessory for use therewith comprising a covering member of insulating material adapted to fit over the open end of the plug without modification of the normal structure of said plug and having openings permitting the covering member to be slipped over the terminals while said terminals are assembled to said body portion, and a plate-like member of insulating material carried by the covering member, and adapted to fit between the said terminals and down into the body of the plug without modification of the normal structure of the plug to separate and insulate the respective terminals and lead-in wires from each other.

2. The combination with substantially any conventional terminal plug for electrical connections of the type having a body portion for the lead in wires and spaced upstanding terminals, a detachable accessory for use therewith comprising a relatively thin plate-like covering member of insulating material adapted to fit over the open end of the plug without modification of the normal structure of said plug and having openings permitting the covering member to be slipped over the terminals while said terminals are assembled to said body portion, and a relatively thin plate-like member of insulating material formed integrally with the covering member and of substantially the same thickness as the covering member, and adapted to fit between the said terminals and down into the body of the plug without modification of the normal structure or" said plug to separate and insulate the respective terminals and lead-in wires from each other.

3. The combination with substantially any conventional terminal plug for electrical connections of the type having a body portion for the lead-in wires and spaced upstanding terminals; a detachable accessory for use therewith comprising a covering member of insulating material adapted to fit over the open end of the plug without modification of the normal structure of said plug and having openings permitting the covering men ber to be slipped over the terminals while said terminals are assembled to said body portion, and a plate-like member of insulating material carried by the covering member, and adapted to fit between the said terminals and down into the body of the plug without modification of thenormal structure of the plug to separate and insulate the respective terminals and lead-in wires from each other; the material of said accessory being of such thickness and structure that it may be readily trimmed and cut with a knife or the like to conform to varying conditions of practical application to diiferent sizes, shapes and types of plugs. 

